Gary, On Tue, Apr 15, 2008 at 10:33 PM, <[EMAIL PROTECTED]> wrote: > Stephane > > Thanks very much for the explanation. > > Just the other day I was wondering how the code in perfmon suspended the > monitored process > while the monitoring was suspended (masked). Now that I find out it allows > the monitored process > to continue executing what is happening becomes much more clear. > > In the first work around you suggested when you say "make the sampling > buffer much bigger" I assume > you are referring to the sampling period which is the counter that controls > how often the overflows occur. > No, I was referring to the actual buffer size. The sampling period is a different thing. Of course, the shorter the period, the more samples you get, thus the pressure on the sampling buffer and thus more blind spots.
If this is the case I have experimented with this value (have tried 1 > million and 1 billion) but it does not > seem to change the results very much. > What this can change is the number of times the buffer fills up, i.e., the number of blind spots. I do not recall in v2.0 if there is a way for you to see the number of buffer full conditions. Looks at /proc/perfmon, maybe there is a metric related to this. > I will use pfmon with sampling and with sampling using process blocking to > verify the results. > > I have looked at the hpcrun help and it does not seem to provide the > ability to block the process > when an overflow occurs. I may need to implement an option like this in > hpcrun to resolve this > problem for our customer. > > If pfmon with sampling behaves as you suggest (and my bets say it will) > then I think we have two > choices. We can either wait for your double buffered version of perfmon or > enhance the hpcrun > to support the ability to block the process while monitoring is suspended. > > I know that I hate to make estimates as to when I will have something done > so I will understand if you > do not want to go there but, any idea when the double buffered perfmon may > be available ? > Double buffering needs a bit of refinements and I don't want to push it into the code base now because people are already complaining about the size of perfmon. ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ perfmon2-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
